How to use

LangFunction

in

org.jaxen.function

private static Boolean evaluate(List contextNodes, Object lang, Navigator nav)
 throws UnsupportedAxisException
{
  return evaluate(contextNodes.get(0), 
    StringFunction.evaluate(lang, nav), nav)
    ? Boolean.TRUE : Boolean.FALSE;
}

private static boolean evaluate(Object node, String lang, Navigator nav)
 throws UnsupportedAxisException
{
  
  Object element = node;
  if (! nav.isElement(element)) {
    element = nav.getParentNode(node);
  }
  while (element != null && nav.isElement(element)) 
  {
    Iterator attrs = nav.getAttributeAxisIterator(element);
    while(attrs.hasNext())
    {
      Object attr = attrs.next();
      if(LANG_LOCALNAME.equals(nav.getAttributeName(attr)) && 
        XMLNS_URI.equals(nav.getAttributeNamespaceUri(attr)))
      {
        return 
          isSublang(nav.getAttributeStringValue(attr), lang);
      }
    }
    element = nav.getParentNode(element);
  }
  return false;
}

new LangFunction() );

"lang", new LangFunction());

"lang", new LangFunction());

return evaluate(context.getNodeSet(), arg, context.getNavigator() );